Attacks in three Iraqi cities last week killed 46 citizens, with the targets Shiite pilgrims and government security forces. The Islamic State of Iraq, a Sunni insurgent group that has styled itself as a local Al Qaeda affiliate, claimed responsibility. Given the targets and methods deployed, that's probably true.

That anticipation did little to save the lives of this week's victims. More than $1 billion has been spent sprucing up Baghdad ahead of the meeting, and the country's government has been getting the word out that Iraq has put its war in its rear-view mirror and the country, as the saying goes, is open for business. But violence has been steadily rising.

The reason why is due to the same problem that the US-led occupation authority had in coming to grips with terror-style attacks at the height of the war in the country between 2004 and 2008: Lots of Iraqis were passively supportive, because they resented the new order, resented the presence of foreign troops, or simply feared retaliation.

The great success of the US "surge" in Iraq was creating conditions that made Iraqis more likely to inform upon a neighbor who, say, suddenly had a strange influx of guests and a lot of banging and welding sounds coming from his garage. Former insurgents were put on the government payroll (financed by the US) when the Sons of Iraq was formed to act as a Sunni counterinsurgency. Promises were made that they'd be integrated into the police or the Army, and that a pluralistic Iraq would emerge that would protect Sunnis from being lorded over by the country's newly empowered Shiite majority.

But in the past few years, Mr. Maliki has accrued more and more power. The Sons of Iraq, also known as the "Sahwa," or "Awakening," have been financially cut off by Maliki's government. And since the US military departed the country at the end of 2011, Maliki has been moving against Sunni politicians.

Sunni Vice President Tariq al-Hashemi is currently in self-imposed exile in autonomous Kurdistan, dodging what he says is a politically motivated warrant for his arrest on terrorism charges. One of Mr. Hashemi's bodyguards, Amir Sarbut Zaidan al-Batawi, died in Iraqi custody. His body was released to his family last week. Human Rights Watch on Friday called for an investigation into Mr. Batawi's death.

“The statements we heard and photos we saw indicate that Iraqi security officers may have tortured Amir Sarbut Zaidan al-Batawi to death while he was in their custody," Joe Stork, the group's deputy Middle East director, was quoted in the statement as saying. The Iraqi government insisted that Batawi died of a natural ailment and that he had refused treatment.

Whatever the exact circumstances may have been, his death – the latest in a string of events alienating Sunni Arabs from the predominately Shiite government of Iraq – has stoked already soaring sectarian mistrust. The more alienated Sunnis feel as a community, the more likely it is that people will take up arms again.

Becca Wasser, a researcher at the International Strategic Studies Institute, has tracked violence in Iraq for the past year. What she's found is a surge in deadly attacks. She writes there were at least 204 bombings in the country from Dec. 19 to March 18 this year, a 70 percent increase over the same period last year, when there were 120. In January, there were 81 bombings, up from 45 in January 2011.

"We’re not arguing the US military should have stayed in Iraq – far from it," Wasser writes. "What the figures do show, along with the information on bombing targets, is that insurgent groups in Iraq are adapting to the new status quo, and that the security and political situation in Iraq remains tenuous."